EP 0811453 A2 19971210 - Focus control of lasers in material processing operations
Title (en)
Focus control of lasers in material processing operations
Title (de)
Laserfokussierungssteuerung in Verarbeitungsoperationen von Materialien
Title (fr)
Commande de la focalisation de lasers dans des opérations de traitement des matériaux
Publication
Application
Priority
GB 9611942 A 19960607
Abstract (en)
When a laser beam interacts with a workpiece to be welded by the beam, a plume of optical radiation is generated. An apparatus and method is disclosed in which radiation from the plume is received back through a beam delivery path comprising optical elements (L1,L2) having chromatic aberration. This alters the focus of different spectral bands of the plume radiation and a discriminating aperture is formed by a face of an optical fibre (3). After passing through the fibre, the plume radiation is separated from any laser radiation and the respective powers of the different spectral bands are measured (5). By subtraction, an error signal is obtained which is used to control the focus of the laser beam. <IMAGE>
IPC 1-7
IPC 8 full level
B23K 26/00 (2006.01); B23K 26/02 (2006.01); B23K 26/03 (2006.01); B23K 26/04 (2006.01); B23K 26/06 (2006.01); B23K 26/08 (2006.01)
CPC (source: EP US)
B23K 26/046 (2013.01 - EP US)
Designated contracting state (EPC)
CH DE FR GB IT LI NL SE
DOCDB simple family (publication)
EP 0811453 A2 19971210; EP 0811453 A3 19980805; EP 0811453 B1 20030502; DE 69721378 D1 20030605; DE 69721378 T2 20031030; GB 9611942 D0 19960807; JP H1052779 A 19980224; US 5850068 A 19981215
DOCDB simple family (application)
EP 97303772 A 19970603; DE 69721378 T 19970603; GB 9611942 A 19960607; JP 14625497 A 19970604; US 86781397 A 19970603